Was it only the rise in weight class, or something else? Because his very impressive KO ratio took a nose-dive when he went up to MW.
Probably the rise in weight. Some guys carry their power up with them, some don't. Also, he wasn't a one punch type guy at 154 except for the Curry left hook. That may have just been a perfect 1/100 punch.
His power never went down at all he was in with bigger guys and had to find otherwise of winning too. Like skill and outboxing them. If you were around him in the gym I bet you'd see no difference in power
Safe to say there was definitely a dip. You don't go from icing Curry to never once dropping Graham (in fact, Herol dropped Mike) without there being a conclusive decline in power. Got worse as he went up. Landed a third of his shots on Jones and never even had him hurt at any point. (Jones also dripped McCallum, actually, so his chin declined as he moved up too.. meaning he was basically a normal human being in terms of following the expected pattern. Guys who retain or improve their attributes moving up are the exceptions..)
He was hitting bigger men. My memory is getting worse and worse but the only fellow that I can think of that seemed to be as effective in terms of power as he moved up is Pac. Can anyone think of anyone else by any chance?
McCallums power had less effect on the bigger guys he was fighting. Still had plenty of skill to get results. It was similar when benn moved up to super middle was fighting boiled down LH weights and his power had less impact so had to box more.
Bigger men absorb it better, plus his level of competition was very high, several with good chins and defensive skills (no one is decking Toney), plus let's face it, age is a factor too - McCallum was getting older when he moved up to middle. He already was 30 years old when he stopped Curry at jr. middle. He was 31 when he moved up in weight and lost the close decision to Kalambay.
There is also the matter of the quality of fighter he fought at middleweight. Toney, Collins, Kalambay and Graham weren't easy guys to stop in their pomp. Kalambay got caught cold against Nunn, but Mike was never a fast starter so that wouldn't happen. Even a guy like Chirino went the distance with Jones Jr in his next fight.
I think it was a combination of age and fighting bigger men. He sure was a skilled fighter though, still made a lot happen even as he got older. I was ringside for his fight against Jeff Harding in 1994 and that was actually a really underrated great fight. He had a gut on him at that point and still went a hard 12 rounds against a younger fighter and controlled the action.